Diagnóstico Prénatal de Hemocromatose Neonatal: Será possível?

Introdução: A Hemocromatose Neonatal é uma doença hepática rara de início intrauterino, definida por insuficiência hepática neonatal associada a siderose extra-hepática. A doença hepática gestacional aloimune foi estabelecida como causa da lesão hepática fetal. Atualmente, não existe uma abordagem eficaz para o diagnóstico prénatal. Caso Clínico: Grávida de 23 anos apresentou às 32 semanas de gestação oligohidrâmnios e focos hepáticos hiperecogénicos. O recém-nascido prematuro desenvolveu falência orgânica multissistémica e faleceu ao segundo dia de vida, apesar de cuidados de suporte intensivos. A autópsia permitiu o diagnóstico de Hemocromatose Neonatal. Conclusão: A identificação ecográfica de focos nodulares hiperecogénicos no fígado fetal pode ser sugestiva de Hemocromatose Neonatal. Investigações adicionais são necessárias para identificar o complexo aloimunitário específico no sangue materno. O estabelecimento do diagnóstico num feto ou recém- -nascido afetado pode ter um grande impacto no prognóstico da doença e no desfecho de futuras gravidezes

Quantum Magnetic Impurities in Magnetically Ordered Systems

We discuss the problem of a spin 1/2 impurity immersed in a spin S magnetically ordered background. We show that the problem maps onto a generalization of the dissipative two level system (DTLS) with two independent heat baths, associated with the Goldstone modes of the magnet, that couple to different components of the impurity spin operator. Using analytical perturbative renormalization group (RG) methods and accurate numerical renormalization group (NRG) we show that contrary to other dissipative models there is quantum frustration of decoherence and quasi-scaling even in the strong coupling regime. We make predictions for the behavior of the impurity magnetic susceptibility that can be measured in nuclear magnetic resonance (NMR) experiments. Our results may also have relevance to quantum computation.Comment: 4 pages, 3 figure

The SARS-CoV-2 Infection Among Students in the University of Porto: A Cross-Sectional Study

Objective: We aimed to quantify SARS-CoV-2 specific antibodies’ seroprevalence among university students in Porto. Methods: A rapid point of care testing for SARS-CoV-2 specific immunoglobulin (Ig) M and IgG antibodies was performed, and a questionnaire was applied to 6512 voluntary students from September to December 2020. We computed the apparent IgM, IgG, and IgM or IgG prevalence, and the true prevalence and 95% credible intervals (95% CI) using Bayesian inference. Results: We found an apparent prevalence (IgM or IgG) of 9.7%, the true prevalence being 7.9% (95% CI 4.9–11.1). Prevalence was significantly higher among males (10.9% vs. 9.2%), international students (18.1% vs. 10.4% local vs. 8.8% nationally displaced), and increased with age. Those with a known risk contact, that experienced quarantine, had symptoms, or a previous negative molecular test had a higher seroprevalence. Of the 91 (1.4%) students who reported a molecular diagnosis, 86.8% were reactive for IgM or IgG. Conclusion: Based on immunological evidence infection was 5.6-fold the reported molecular diagnosis. The higher seroprevalence among male, older, and international students emphasizes the importance of identifying particular groups. Copyright © 2022 Meireles, Costa, Novais, Miranda, Lopes, Severo and Barros.This study was funded by University of Porto and supported by national funds of Fundação para a Ciência e Tecnologia, under the scope of the projects UIDB/04750/2020—Research Unit of Epidemiology–Institute of Public Health of the University of Porto (EPIUnit) and LA/P/0064/2020–Laboratory for Integrative and Translational Research in Population Health (ITR). JPC was the recipient of PhD grant (DFA/BD/8562/2020) co-funded by the national funds of Fundação para a Ciência e Tecnologia and the Fundo Social Europeu

The usefulness of ecotoxicological tools to improve the assessment of water bodies in a climate change reality

This study aimed to analyse the added value of using ecotoxicological tools to complement and improve the assessment of natural water bodies status, in situations of climate change, with a higher frequency of extreme events as floods or droughts. Four water bodies of streams in the Guadiana Basin (Álamos, Amieira, Lucefécit, Zebro) were studied in 2017 and 2018 and classified based on the Water Framework Directive (WFD) parameters: Biological Quality Element - Phytobenthos (diatoms), General chemical and physicochemical elements, Specific pollutants, and Priority Substances. Complementarily, bioassays (including lethal and sublethal parameters) were carried out with organisms of different trophic levels: (i) the bacteria Aliivibrio fischeri; (ii) the microalgae Pseudokirchneriella subcapitata; (iii) the crustaceans Daphnia magna, Thamnocephalus platyurus and Heterocypris incongruens. A classification system with 5 scores was developed, permitting to classify water bodies from non-toxic (EC50 > 100 %; growth and feeding rate > 80 %; blue) to highly toxic (EC50 < 10 %; growth and feeding rate < 10 %; red). The comparison between the classification based on the WFD parameters and on ecotoxicological endpoints showed similar results for 71 % of the samples, and significant positive Pearson correlations were detected between the diatom-based Specific Polluosensitivity Index (SPI) and EC50V.fisheri, the algae growth rate and Shannon diversity index. These results indicate that when the biological quality elements cannot be used (namely under drought or flooding conditions) the application of ecotoxicological bioassays may be a good alternative. Further, when ecotoxicological parameters were included, an increase of worse classifications (Bad and Poor) was observed, revealing an improvement in the sensitivity of the classification, mainly in presence of specific and priority substances. So, the ecotoxicological analysis appears to provide useful information regarding the potential presence of both known and unknown contaminants at concentrations that cause biological effects (even within the WFD limits), in agreement with several authors that have already suggested its use in biomonitoring

Cork derived TiO2 biomorphic ecoceramics

Environmentally conscious biomorphic ceramics (Ecoceramics) are a new class of material manufactured from renewable resources and wastes. Sustainable cork wastes were pyrolysed, and this activated carbon template infiltrated with a sol-gel precursor (from aqueous green-chemistry) to form TiO2 on heating in air, with the honeycomb microstructure of cork. Physical and optical band gap properties were characterised by XRD, SEM and Raman and UV–vis spectroscopy, and differences between alkaline and acidic activation of the carbon template also studied. With activation by HCl, HNO3 or H2SO4, a mixture of anatase and rutile formed. NaOH activation resulted in pure anatase, but a large amount of Na was retained. At 1000 °C acid activated ecoceramics formed pure rutile, but the NaOH activated one formed Na2Ti6O13 (sodium hexatitanate) as the major phase, coexisting with anatase, brookite and rutile. This material is worth further investigation, as Na2Ti6O13 is reported as a photocatalyst in its own right

Small Fermi surface in the one-dimensional Kondo lattice model

We study the one-dimensional Kondo lattice model through the density matrix renormalization group (DMRG). Our results for the spin correlation function indicate the presence of a small Fermi surface in large portions of the phase diagram, in contrast to some previous studies that used the same technique. We argue that the discrepancy is due to the open boundary conditions, which introduce strong charge perturbations that strongly affect the spin Friedel oscillations.Comment: 5 pages, 7 figure

Tetracyclic thioxanthene derivatives: Studies on fluorescence and antitumor activity

Thioxanthones are bioisosteres of the naturally occurring xanthones. They have been described for multiple activities, including antitumor. As such, the synthesis of a library of thioxanthones was pursued, but unexpectedly, four tetracyclic thioxanthenes with a quinazoline– chromene scaffold were obtained. These compounds were studied for their human tumor cell growth inhibition activity, in the cell lines A375-C5, MCF-7 and NCI-H460. Photophysical studies were also performed. Two of the compounds displayed GI50 values below 10 µM for the three tested cell lines, and structure–activity relationship studies were established. Three compounds presented similar wavelengths of absorption and emission, characteristic of dyes with a push-pull character. The structures of two compounds were elucidated by X-ray crystallography. Two tetracyclic thioxanthenes emerged as hit compounds. One of the two compounds accumulated intracellularly as a bright fluorescent dye in the green channel, as analyzed by both fluorescence microscopy and flow cytometry, making it a promising theranostic cancer drug candidate.This research was partially supported by the Strategic Funding UIDB/04423/2020, UIDP/04423/2020 (Group of Natural Products and Medicinal Chemistry‐CIIMAR) and under the project PTDC/SAU‐PUB/28736/2017 (reference POCI‐01‐0145‐FEDER‐028736), co‐financed by COMPETE 2020, Portugal 2020 and the European Union through the ERDF and by FCT through national funds. Fernando Durães acknowledges his FCT grant (SFRH/BD/144681/2019). Hassan Bousbaa acknowledges funding from CESPU (IMPLDEBRIS‐PL‐3RL‐IINFACTS‐2019). This research was funded by Fundação para a Ciência e a Tecnologia (FCT) through research units UIDB/50006/2020, UID/CTM/50011/2019, UIDB/50011/2020 & UIDP/50011/2020 and by the European Union (FEDER program) through project CENTRO‐01‐0145‐FEDER‐000003

Hamiltonian Formulation of Quantum Error Correction and Correlated Noise: The Effects Of Syndrome Extraction in the Long Time Limit

We analyze the long time behavior of a quantum computer running a quantum error correction (QEC) code in the presence of a correlated environment. Starting from a Hamiltonian formulation of realistic noise models, and assuming that QEC is indeed possible, we find formal expressions for the probability of a faulty path and the residual decoherence encoded in the reduced density matrix. Systems with non-zero gate times (``long gates'') are included in our analysis by using an upper bound on the noise. In order to introduce the local error probability for a qubit, we assume that propagation of signals through the environment is slower than the QEC period (hypercube assumption). This allows an explicit calculation in the case of a generalized spin-boson model and a quantum frustration model. The key result is a dimensional criterion: If the correlations decay sufficiently fast, the system evolves toward a stochastic error model for which the threshold theorem of fault-tolerant quantum computation has been proven. On the other hand, if the correlations decay slowly, the traditional proof of this threshold theorem does not hold. This dimensional criterion bears many similarities to criteria that occur in the theory of quantum phase transitions.Comment: 19 pages, 5 figures. Includes response to arXiv:quant-ph/0702050. New title and an additional exampl